66421401 has 16 divisors (see below), whose sum is σ = 94913664. Its totient is φ = 41209344.

The previous prime is 66421379. The next prime is 66421403. The reversal of 66421401 is 10412466.

It is not a de Polignac number, because 66421401 - 2²² = 62227097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66421403) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10456 + ... + 15561.

It is an arithmetic number, because the mean of its divisors is an integer number (5932104).

Almost surely, 2^66421401 is an apocalyptic number.

It is an amenable number.

66421401 is a deficient number, since it is larger than the sum of its proper divisors (28492263).

66421401 is a wasteful number, since it uses less digits than its factorization.

66421401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26080.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 66421401 is about 8149.9325764082. The cubic root of 66421401 is about 404.9822702191.

Adding to 66421401 its reverse (10412466), we get a palindrome (76833867).

The spelling of 66421401 in words is "sixty-six million, four hundred twenty-one thousand, four hundred one".